"Alaska expects domestic travel to return to pre-COVID levels by the summer of 2022, which will require more aircraft across Air Group," the company said in a statement.
The orders for the 737-9 MAX are part of Alaska Air's purchase options from December, when it had ordered 23 of the MAX airplanes.
The company expects to take deliveries of nine out of 13 737-9 MAX planes in 2023, and four in 2024.
Alaska Air said the 17 Embraer 175 jets will grow its regional fleet to 111 planes, with deliveries in 2022 and 2023.
(Reporting by Ankit Ajmera in Bengaluru; Editing by Shailesh Kuber)